1. Field of the Invention
The present invention generally relates to a device for automatically feeding household pets and, more particularly but not by way of limitation, to such an apparatus having pressure sensitive mechanisms to determine when food and water bowls are to be automatically refilled.
2. Description of the Related Art
U.S. Pat. No. 4,315,483, issued to Scheidler, discloses an animal feeder which dispenses feed when less than a predetermined amount of food product is received by a trough, until the predetermined amount is again received by the trough. A control system is employed whereby the food trough, as it is filled with food product, forces a set of electrical contacts to come open, thus deenergizing a food dispensing circuit. When enough food is consumed by an animal, the trough springs force the trough upward to reclose the electrical contacts, activating a timer, and subsequently dispensing more food product.
U.S. Pat. No. 4,069,793, issued to Gower, discloses a pet feeding apparatus having a plurality of food containing tubes, each of which is opened at set intervals by a trap door held closed by a retractable plunger of an electrical relay. Upon receiving a signal from a timing circuit, the relay plunger is retracted, thus allowing the trap door to open by gravity and dispensing a predetermined amount of food. At the same time, a solenoid valve is opened for a fixed time interval to drain water from a water tank to mix with the pet food and to supply drinking water for the pet. This device, however, requires the user to manually reset the trap door and relay, as well as fill the food tubes each time food has been dispensed.
Other U.S. Patents of interest include the following: U.S. Pat. No. 2,791,984 issued to Franklin; U.S. Pat. No. 3,171,385 issued to Decker et. al.; U.S. Pat. No. 3,527,191 issued to Kawecki et. al.; U.S. Pat. No. 3,638,618 issued to Strother; U.S. Pat. No. 3,949,909 issued to Sterner; U.S. Pat. No. 4,182,273 issued to Peterson; U.S. Pat. No. 4,279,221 issued to Arvizu; U.S. Pat. No. 4,284,035 issued to White; U.S. Pat. No. 4,513,688 issued to Fassauer; U.S. Pat. No. 4,756,277 issued to Peng; U.S. Pat. No. 4,722,300 issued to Walker et. al.; and U.S. Pat. No. 4,782,790 issued to Batson.